JPH0459897B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a spiral flat coil for shock wave tubes and a method for manufacturing the same. The flat coil according to the invention is used in particular for shock wave tubes for fragmenting stones, such as kidney stones, in patients.

[Conventional technology]

Shock tubes of this type have been known for quite some time (publication "Akustische Beihefte", published in 1962, no. 1).
(See pages 185-202). This shock wave tube is used in medical technology for breaking up stones in the body of a patient on the basis of a new diagnosis method, such as that disclosed in German Patent Application No. 3312014, for example. German Patent Application No. 3312014 discloses a shock wave tube that can be used for this purpose. Due to the high pressure pulses, such as approximately 100 bar, the material of the shock wave tube is highly stressed during each shock wave release. In particular, the discharge coil and diaphragm are subjected to high mechanical forces. In German Patent Application No. 3312014, a bulb-shaped coil is provided, but the bulb-shaped coil is made by additional processing such as hollowing out a flat coil.

[Problem that the invention seeks to solve]

However, such machining methods naturally involve high material costs and also require machining tools that are demanding, for example with respect to precision.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a manufacturing method and a flat coil of the type mentioned at the beginning, by which a flat coil having an arbitrary spiral shape can be manufactured by simple means.

[Means for solving problems]

To achieve this objective, the present invention provides a method for photographic printing in which a spiral-shaped shielding film is applied to a printed board having a support film, a conductive film located above the support film, and a photosensitive upper film. The upper film is developed, the area between the spirals of the transferred shielding film is etched away from the conductive film, the spirals left in the conductive film are strengthened by electroplating, and finally the printed board is formed. is attached to a flat coil support.

The flat coil manufactured by the manufacturing method of the present invention includes a support film, a spiral made of copper fixed to the support film, and a plate-shaped body made of an acoustically reflective non-conductive material and provided as a support for the flat coil. and a spiral and/or a support film are attached to this plate-like body.

An advantage of the manufacturing method according to the invention is that coils with arbitrary spiral shapes can be manufactured without any problems. For this purpose, no expensive mechanical processing tools, such as lathes or milling machines, are required.

According to a particularly advantageous embodiment of the manufacturing method according to the invention, the printed circuit board is glued with its spiral-bearing surface to a flat coil carrier. In this way, the non-conductive parts of the printed circuit board can be used in shock tubes at the same time as an insulating layer between the coil and the diaphragm supported in front of the coil. The installation of the main components of the shock tube, namely the flat coil, the insulation membrane and the diaphragm, is thereby significantly simplified.

〔Example〕

Next, embodiments of the present invention will be described in detail based on the drawings.

For the sake of simplicity, the individual film thicknesses are not shown to scale in the drawings. This is clear from the explanation below.

In FIG. 1, reference numeral 1 designates the entire shock wave tube, the main components of which are a flat coil support 3 having a spiral coil 4 (see FIGS. 3 and 4), an insulating film 5 and a diaphragm 7. A means for holding the coil 4, insulating film 5, and diaphragm 7 is not shown.

In order to generate a shock wave, the flat coil 4 is given a high voltage pulse for a short period of time. Based on the electromagnetic interaction between the coil 4 and the diaphragm 7,
The diaphragm 7 is pushed away from the coil 4. This causes the diaphragm 7 to generate a shock wave. In order for the shock tube 1 to function well and to produce a certain desired waveform, the coil 4 must have a defined shape. The surface of the coil 4 may be formed into a planar shape, for example, if it is desired to generate a planar shock wave, or may be formed into a concave spherical shape if the generated shock wave is desired to travel so as to converge at one point. In addition to forming the coil 4 in a defined shape, it is very important that the insulation between the spiral paths (conductors making up the spiral coil) is well formed, for example without enclosing air. The voltage pulse applied to the coil 4 has a magnitude of about 10 to 30 kV.

The production of the flat coil support 3 with the coil 4 starts from a circular ceramic plate. For example, with a diameter of 155 mm, this disk has a thickness of 40 mm. However, when implementing the method described above,
For a thickness of 15 mm, small discs with a diameter of, for example, 60 mm are also produced. In addition to this circular plate made of ceramic and used as flat coil support 3, a printed circuit board 9 is used as a further starting material. This printed board 9 is provided for manufacturing the coil 4. The printed circuit board 9 consists of a non-conductive support film 11, preferably made of polyimide. This polyimide membrane can have a thickness of about 200 μm. On one side of the support membrane 11, a thin film 13 made of an electrically conductive material, in particular about 7 μm thick, is provided.
A copper film with a thickness of . A photosensitive upper film 15 is further provided on this copper film 13.

FIG. 2 shows a flat coil support 3 and a printed board 9 processed according to the first and second steps.
is shown. Depending on the type of photosensitive upper film 15, a shielding film (not shown) containing a spiral shape by a positive or negative manufacturing method is placed, and then the parts of the photosensitive film 15 that are not covered by the shielding film are placed. The spiral path 13a is exposed to light.
By developing and etching away the gaps between the two, the printed board 9 shown in FIG. 2 is constructed. This printed board 9 is composed of a support film 11 and a portion of the copper film 13 that was originally present. As a result, the spiral path 13a forms a spiral flat coil 4.

In addition to the flat coil support 3, in FIG.
A spiral copper film 13 is shown enhanced to a total thickness of 150 μm. The spiral having the spiral path 13a created in this way has individual spiral paths 13a.
If they have sufficient spacing, they can withstand high voltage and high current shocks during shock wave generation.

In FIG. 4, the complete device with flat coil support 3 and integrated coil 4 is shown. The gaps between the spiral copper films 13 are filled with synthetic resin 17. The coil 4 is glued to the end face of the flat coil support 3. In order to better adhere the coil 4 to the flat coil support 3 and to fill the gap with synthetic resin, the entire end face of the flat coil support 3 can likewise be applied with synthetic resin in one working step.

In principle, the printed board 9 is attached to the flat coil support 3 by a support film 11 or by a film 13.
But it can also be glued. The advantage of this second embodiment is that the support membrane 11 can be used at the same time as the insulating membrane 5 in order to electrically insulate the coil 4 from the diaphragm 7.

A particularly suitable material for the flat coil support 3 is aluminum oxide ceramic, in which case good results can be obtained with or without filling with epoxy resin.

〔Effect of the invention〕

As explained above, according to the present invention, a flat coil having an arbitrary spiral shape can be manufactured without any problems. Moreover, for this reason,
No expensive mechanical processing tools, such as lathes or milling machines, are required.

[Brief explanation of the drawing]

FIG. 1 is an exploded view showing a shock wave tube having a printed circuit board and a diaphragm bonded to a coil support and an insulating film, and FIG. 2 is a printed circuit board in which the gap between the coil support and the spiral path has been etched away. FIG. 3 is a schematic diagram showing a coil support and a spiral track reinforced by electroplating; FIG. 4 is a schematic diagram showing a coil support and a spiral track reinforced by electroplating; FIG. FIG. 2 is a schematic diagram showing a completed flat coil device consisting of a spiral coil and a spiral coil. DESCRIPTION OF SYMBOLS 1... Shock wave tube, 3... Flat coil support, 4... Coil, 5... Insulating film, 7... Diaphragm, 9... Printed board, 11... Support film, 1
3... Copper film, 13a... Spiral path, 15... Photosensitive upper film, 17... Synthetic resin.

Claims (1)

[Claims] 1. A method for manufacturing a spiral flat coil for a shock wave tube, in which a spiral shielding film comprises a support film 11 and a conductive film 1 located on the support film.
3 and a photosensitive upper film 15, the upper film 15 is developed, and the area between the spiral paths 13a of the transferred shielding film is etched away from the conductive film 13. A method for manufacturing a flat coil for a shock wave tube, characterized in that the spiral path 13a left on the conductive film 13 is strengthened by electroplating, and finally a printed board 9 is attached to the flat coil support 3. 2 A polyimide film is provided as the support film 11,
2. A method according to claim 1, characterized in that a copper film is provided as the conductive film 13. 3 The polyimide film 11 has a thickness of about 200 μm,
3. A method according to claim 2, characterized in that the copper film 13 has a thickness of approximately 7 μm. 4 The spiral path 13a is approximately 150 μm thick by electroplating.
A method according to any one of claims 1 to 3, characterized in that the thickness is increased to . 5. The method according to any one of claims 1 to 4, characterized in that the surface of the printed board 9 supporting the spiral path 13a is adhered to the flat coil support 3. 6 comprises a support film 11, a spiral path 13a made of copper and fixed to the support film 11, and a plate-shaped body made of an acoustically reflective non-conductive material and provided as a flat coil support 3; A flat coil for a shock wave tube, characterized in that the spiral path 13a and/or the support film 11 are attached. 7. The flat coil according to claim 6, wherein the flat coil support 3 is made of ceramic. 8. The flat coil according to claim 6, wherein the flat coil support 3 is made of epoxy resin. 9 Spiral path 13a and/or
A flat coil according to any one of claims 6 to 8, characterized in that a resin 17 is provided for adhering the support film 11.